Apache Hive Query Component

Apache Hive Query

This component retrieves data on a Apache Hive data warehouse and loads it into a table. This stages the data, so the table is reloaded each time. You may then use transformations to enrich and manage the data in permanent tables.

Since basic authentication is optional for Apache Hive servers, Username and Password properties are not present on this component. To add a Username and Password, use the Connection Option property to set those values.

Warning: This component is potentially destructive. If the target table undergoes a change in structure, it will be recreated. Otherwise, the target table is truncated. Setting the Load Option 'Recreate Target Table' to 'Off' will prevent both recreation and truncation. Do not modify the target table structure manually.

Properties

Property

Setting

Description

Name

Text

The descriptive name for the component.

Basic/Advanced Mode

Choice

Basic - This mode will build a Query for you using settings from Data Source, Data Selection and Data Source Filter parameters. In most cases, this will be sufficient.Advanced - This mode will require you to write an SQL-like query to call data from Apache Hive. The available fields and their descriptions are documented in the data model.

Server

Text

Address of the Apache Hive server from which data is to be sourced.

Port

Text

The port to be used to access the Apache Hive server.

Data Source Filter

Input Column

The available input columns vary depending upon the Data Source.

Qualifier

Is - Compares the column to the value using the comparator.
Not - Reverses the effect of the comparison, so "equals" becomes "not equals", "less than" becomes "greater than or equal to", etc.

Comparator

Choose a method of comparing the column to the value. Possible comparators include: 'Equal To', 'Greater than', 'Less than', 'Greater than or equal to', 'Less than or equal to', 'Like', 'Null'.
'Equal To' can match exact strings and numeric values while other comparators such as 'Greater than' will work only with numerics. The 'Like' operator allows the wildcard character (%) to be used at the start and end of a string value to match a column. The Null operator matches only Null values, ignoring whatever the value is set to.
Not all data sources support all comparators, thus it is likely only a subset of the above comparators will be available to choose from.

Value

The value to be compared.

SQL

Text

Custom SQL-like query only available during 'Advanced' mode.

Limit

Number

Limits the number of rows that are loaded from file.

Connection Options

Parameter

A JDBC parameter supported by the Database Driver. The available parameters are determined automatically from the driver, and may change from version to version.
They are usually not required as sensible defaults are assumed.

Value

A value for the given Parameter.

Storage Account

Select

(Azure Only) Select a Storage Account with your desired Blob Container to be used for staging the data.

Blob Container

Select

(Azure Only) Select a Blob Container to be used for staging the data.

Staging

Select

(AWS Only) Snowflake Managed: Allow Matillion ETL to create and use a temporary internal stage on Snowflake for staging the data. This stage, along with the staged data, will cease to exist after loading is complete.Existing Amazon S3 Location: Selecting this will avail the user of properties to specify a custom staging area on S3.

S3 Staging Area

Text

(AWS Only) The name of an S3 bucket for temporary storage. Ensure
your access credentials have S3 access and permission to write
to the bucket. See this document for
details on setting up access. The temporary objects created in this bucket will be removed again after the load completes, they are not kept.This property is available when using an Existing Amazon S3 Location for Staging.

Warehouse

Select

Choose a Snowflake warehouse that will run the load.

Database

Select

Choose a database to create the new table in.

Type

Select

Choose between using a standard table or an external table.Standard: The data will be staged on an S3 bucket before being loaded into a table.External: The data will be put into an S3 Bucket and referenced by an external table.

Schema

Select

Select the table schema. The special value, [Environment Default] will use the schema defined in the environment. For more information on using multiple schemas, see this article.

Note: An external schema is required if the 'Type' property is set to 'External'.

Target Table

Text

Provide a new table name.Warning: This table will be recreated and will drop any existing table of the same name.

Location

Text/Select

When using an 'External' type table, Provide an S3 Bucket path that will be used to store the data. Once on an S3 bucket, the data can be referenced by the external table.

Distribution Style

Select

Even - the default option, distribute rows around the Redshift Cluster evenly.All - copy rows to all nodes in the Redshift Cluster.Key - distribute rows around the Redshift cluster according to the value of a key column.
Table-distribution is critical to good performance - see the Amazon Redshift documentation for more information.

Sort Key

Select

This is optional, and specifies the columns from the input that should be set as the table's sort-key.
Sort-keys are critical to good performance - see the Amazon Redshift documentation for more information.

Load Options

Multiple Selection

Comp Update: Apply automatic compression to the target table (if ON). Default is ON.Stat Update: Automatically update statistics when filling a table (if ON). Default is ON. In this case, it is updating the statistics of the target table.Clean S3 Objects: Automatically remove UUID-based objects on the S3 Bucket (if ON). Default is ON. Effectively decides whether to keep the staged data in the S3 Bucket or not.String Null is Null: Converts any strings equal to "null" into a null value. This is case sensitive and only works with entirely lower-case strings. Default is ON.Recreate Target Table:Choose whether the component recreates its target table before the data load. If OFF, the existing table will be used. Default is ON.

Project

Text

The target BigQuery project to load data into.

Dataset

Text

The target BigQuery dataset to load data into.

Cloud Storage Staging Area

Text

The URL and path of the target Google Storage bucket to be used for staging the queried data.

Encryption

Select

(AWS Only) Decide on how the files are encrypted inside the S3 Bucket.This property is available when using an Existing Amazon S3 Location for Staging.None: No encryption.SSE KMS: Encrypt the data according to a key stored on KMS.SSE S3: Encrypt the data according to a key stored on an S3 bucket

KMS Key ID

Select

(AWS Only) The ID of the KMS encryption key you have chosen to use in the 'Encryption' property.

Choose whether to automatically log debug information about your load. These logs can be found in the Task History and should be included in support requests concerning the component. Turning this on will override any debugging Connection Options.

Debug Level

Select

The level of verbosity with which your debug information is logged. Levels above 1 can log huge amounts of data and result in slower execution.1: Will log the query, the number of rows returned by it, the start of execution and the time taken, and any errors.2: Will log everything included in Level 1, cache queries, and additional information about the request, if applicable.3: Will additionally log the body of the request and the response.4: Will additionally log transport-level communication with the data source. This includes SSL negotiation.5: Will additionally log communication with the data source and additional details that may be helpful in troubleshooting problems. This includes interface commands.

Variable Exports

This component makes the following values available to export into variables:

Source

Description

Time Taken To Stage

The amount of time (in seconds) taken to fetch the data from the data source and upload it to storage.

Time Taken To Load

The amount of time (in seconds) taken to execute the COPY statement to load the data
into the target table from storage.

Strategy

Connect to the target database and issue the query. Stream the results into objects on S3. Then create or truncate the target table and issue a COPY command to load the S3 objects into the table. Finally, clean up the temporary S3 objects.